A member of the gens Artoria (possibly of Messapic or Etruscan origin), he has been suggested as a potential historical basis for King Arthur.

What is known of Artorius comes from inscriptions on fragments of a sarcophagus, and a memorial plaque, found in Podstrana, on the Dalmatian coast in Croatia.

Although the inscriptions cannot be precisely dated, Lucius Artorius Castus probably served in the Roman army sometime between the mid-late 2nd century AD or early-to-mid 3rd century AD.

When his military career and exploits are compared with those of Arthur there is some similarity. The two known inscriptions that detail the career of Lucius Artorius Castus place him firmly in Britain as a soldier who at one point in his career held the title "dux".

While Arthur's title dux was eventually supplanted by rex ("king"), dux was clearly his original rank, and the development from dux to rex follows a direct line of transmission.

Lucius Artorius Castus does not mirror every detail of the Arthurian legends, however the parallels between King Arthur and Lucius Artorius Castus are striking across a range of details, both large and small.